Adolescence is considered as the time full of “storm and stress” and characterized by fluctuations of mood states. Two laboratory experiments were conducted to elucidate the differences of up-regulation and down-regulation effects between adolescents and adults toward emotional stimuli of various valence (positive/neutral/negative) and arousal (high/low). It’s hypothesized and verified that adults have larger regulation effect size than adolescents. 　　Study 1 used a 2（age: adolescents/adults, between subject）? 3(emotional valence: positive/negative/neural, within subject) ? 3(emotion regulation strategy: up regulation/down regulation/no regulation, within subject) mixed design. The Reactivity and Regulation-Image Task (REAR-I Task; Carthy, Horesh, Apter, Edge, & Gross, 2010) was utilized upon 35 adolescents and 35 adults to exam their up-regulation and down-regulation effects of positive, neutral, and negative emotional stimuli. Results showed that: (1) besides the similar effects of negative emotion up regulation between adolescents and adults, the other three regulation effect sizes were larger in adults than in adolescents. However, negative emotion up regulation by definition is not an adaptive kind of emotion regulation; (2) effect sizes of emotion regulation in adults were from medium to large. Specifically, in the negative emotional condition, adults presented a fairly large effect size (0.91) of down-regulation. The regulation effect sizes of adolescents were from small to medium. 　　Study 2 further differentiate emotion stimuli into high-arousal group and low-arousal group by the SAM paradigm（Bradley & Lang, 1994）. Then REAR-I Task was utilized upon 59 adolescents and 59 adults to exam their up-regulation and down-regulation effects towards different valenced (positive/neutral/negative) and aroused (high/low) emotional stimuli. Results showed that: (1) effect sizes of high arousal emotion up regulation and low arousal positive emotion up regulation in adolescents and in adults were similar; (2) effect sizes of down regulation in adults were all larger than in adolescents. Specifically, in high arousal negative emotion down regulation condition, the effect sizes of adolescents were near to the large effect; (3) effect sizes of up-regulation were similar with the effect sizes of down-regulation in adolescents; on the contrary, down-regulation effect sizes were larger than the up-regulation effect sizes in adults; (4) when up-regulating high arousal emotions, effect sizes of adolescents were larger than adults. When making down-regulation, effect sizes of adults were larger than adolescents.